Field of the Invention
The present invention relates to a mass spectrometry method applicable to medical field and drug discovery field, and especially relates to MALDI-MS (Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry) application. More precisely, the present invention relates to a mass spectrometry method using a specific compound as a matrix additive, and a matrix additive for mass spectrometry.
Disclosure of the Related Art
Conditions for achieving efficient ionization of a molecule to be analyzed in MALDI (Matrix-Assisted Laser Desorption/Ionization) mass spectrometry have been researched.
For example, JP-A-2005-326391 (Patent Document 1) discloses a method in which a hydrophobic peptide, especially an NBS-modified peptide obtained by previously modifying a peptide with 2-nitrobenzenesulfenyl (NBS) group, is subjected to mass spectrometry using, as a matrix, α-cyano-3-hydroxycinnamic acid (3-CHCA), 3-hydroxy-4-nitrobenzoic acid (3H4NBA), or a mixture of them so that the hydrophobic peptide is more efficiently ionized as compared to when a general matrix such as α-cyano-4-hydroxycinnamic acid (4-CHCA) or 2,5-dihydrobenzoic acid (DHB) is used.
J. Agric. Food Chem., 2004, 52(16), pp. 5011-5020 (Non-Patent Document 1) discloses alkyl esters of 3,4-dihydroxybenzic acid as food additives.
Biotechnology Letters, Vol. 19, No. 6, June 1997, pp. 529-532 (Non-Patent Document 2) discloses the yield of esterification between 2,5-dihydroxybenzoic acid and octanol.    Patent Document 1: JP-A-2005-326391    Non-Patent Document 1: Journal of Agricultural and Food Chemistry, 2004, Vol. 52, No. 16, pp. 5011-5020    Non-Patent Document 2: Biotechnology Letters, June 1997, Vol. 19, No. 6, pp. 529-532